At least due to their small-size, multifunctionality, and/or low-cost characteristics, semiconductor devices are considered important elements in the electronic industry. The semiconductor devices can be generally classified into a memory device for storing data, a logic device for processing data, and a hybrid device capable of performing various functions.
There is an increasing demand for a semiconductor device with a higher integration density and higher performance. Although a variety of studies are being conducted to meet such a demand, it is desired to reduce a process margin (for example, in a photolithography process) and this may lead to several difficulties in fabricating a semiconductor device.